Wide bandwidth lightwave communication systems using optical fiber transmission channels require converting outgoing information signals from electrical to lightwave form and conversion of incoming information signals from lightwave to electrical form at each terminal end of the channel. Opto-electronic termination equipment generally includes both electronic circuitry and an assembly of opto-electronic and optical devices interconnected by optical fibers. Optical fibers, however, are usually small in diameter, brittle and have transmission characteristics that may be adversely affected by splicing and bending beyond a prescribed minimum bend radius. Consequently, it is necessary to use special handling techniques to assure reliable interconnection without impairment of the lightwave signals.
In view of the difficulties present in connecting optical fibers to lightguide connectors and to opto-electronic devices, the optical signal portion of termination equipment has generally been separated from the printed circuit cards on which the electrical termination functions are performed. The separation allows adequate space needed for assembly and repair of high quality optical interconnections without interfering with automatic assembly of electronic components on the printed circuit cards. Where mixing of both optical and electrical functions are required on a printed circuit card, the card must be adapted to accommodate optical fiber interconnections by special mounting arrangements for the opto-electronic devices and optical connectors.
U.S. Pat. 4,461,537, issued to Jack D. Raymer et al. on July 24, 1984, discloses an opto-electronic device incorporated in a fiber optic connector assembly that includes an optical port, an optical lens and means for guiding a fiber end into alignment with the lens mounted on a printed circuit board. The arrangement uses a simple optical fiber structure on the printed circuit card that is adjusted to an only single opto-electronic conversion. The connector assembly, however, is not suitable for optical interconnections requiring a high degree of accuracy or for more complex optical interconnections such as used in communication systems.
Other arrangements incorporating both fiber optic and electronic components on a printed circuit card such as described in U.S. Pat. 4,217,030, issued to Louis E. Howarth on August 12, 1980, include only simple optical fiber interconnection patterns to avoid impairment of lightwave transmission characteristics. Thus, while intricate electrical conductor patterns are used to interconnect electronic components within a limited space on a printed circuit card, only relatively simple and direct connections to optical fibers are permitted.
U.S. Pat. 4,432,604, issued to Richard E. Schwab on February 21, 1985, describes a self-adjusting fiber optic connector assembly having optical fibers extending therefrom to opto-electronic devices mounted on a printed circuit card wherein the optical fiber and electrical connections are made on the board. The self-adjusting connectors permit changes in placement of optical fibers on a printed circuit card but are not adapted to complex optical fiber arrangements and do not permit controlled looping of interconnecting optical fibers. It is an object of the invention to provide an improved opto-electronic assembly arrangement that permits automatic assembly of relatively complex optical fiber interconnections on a printed circuit card.